Plenty of industries require workers to enter and temporarily work in confined areas, and it is not just claustrophobia that can cause problems there. Many confined spaces can be potentially hazardous, because of their design or their contents.

There are strict requirements about how such spaces can be used, and they must be tested for hazards before being entered. In the US, the Occupational Safety and Health Administration (OHSA) is the government body responsible for supervising these requirements.

What is a Confined Space?

The OHSA has the following definition of a confined space: ‘one that is large enough to enter and perform assigned work in; it has limited or restricted ways to enter or exit the space; and it was not designed to be occupied continuously by a worker.’ If there is a confined space in the workplace, there are two tests that are required to keep it safe for the staff.

First, there must be an Evaluation Test. This must be carried out using appropriate equipment to test levels of hazardous chemicals, and the presence of other hazards. The results must be evaluated or reviewed by a person with professional qualifications recognized by the OHSA.

If the space is evaluated as posing potential health or safety hazards, it is designated a ‘permit space.’ A permit will be issued and when the space is used a Verification Test must be carried out, according to the requirements of the permit, by testing for oxygen, combustible gases, and toxic gases and vapors.

How are the Tests Carried Out?

The atmospheric tests are carried out with a suitable meter. This may be a device that tests for a single gas, or a multi gas monitor. The manufacturer’s operating manual will provide instructions on how to use it, and it is important that these are followed carefully.

The manual will identify a ‘minimum response time,’ which is the minimum time necessary for the gas to pass into the equipment’s sensor and be measured. Where the atmosphere is sucked into the monitor through a tube or nozzle, extra time must be allowed.

In larger spaces the atmosphere must be tested in several locations or layers, or by moving slowly through the space. If required, this should be identified on the permit.

What Mistakes Can be Made?

Although environmental, health, and safety (EHS) issues are primarily the responsibility of employers, it pays for all members of staff to be aware of the requirements, and to have a culture where corners are not cut. The same goes for the self-employed—it is not worth taking risks with EHS. It is easy to slip up, so it is a good idea to be conscious of the mistakes that are often made.

Too many people are ignorant of the OSHA guidelines and requirements, or are ready to ignore them. It is reckoned that if these were followed precisely, the accidents that currently occur would effectively be eliminated.

It is an easy mistake to misuse the equipment. As we know with our household devices, when we think we know how to work them we develop our own methods, which may not be those recommended by the manufacturer. This might be good enough for our TV, but it won’t do for essential EHS equipment.

Or if we think we know the space well enough, we might be tempted not to use the equipment at all, but go by our own experience. For instance, we might know that levels of a particular gas are always lower at a certain stage of the working week, so not bother to carry out a test. Or we might rely on our own sense of smell.

Once we are inside the space, we might forget to check the monitor. Levels of hazardous gases can change quite rapidly, and this is where a clip-on monitor is helpful, provided we actually use it.

t is a mistake to work entirely alone in a potentially hazardous confined space. We should always have a buddy who remains outside the space and is able to maintain contact, fetching help if required. For the same reason it is important to have a clearly understood, and rehearsed, procedure for dealing with an emergency. Some of the victims of confined space fatalities are other employees rushing in to help their co-workers.

Work Wise, Work Safe

Employers have full responsibility for the safety of their workers, but everyone should play a part. Confined space work is just one aspect of that task, and not every workplace involves confined spaces; but where they are present, knowledge of correct procedures can avoid potential disasters and keep the working environment safe.

Jayden Baldwin works in an occupational safety role, travelling around places of work carrying out risk assessments to ensure the safety of employees. In his spare time he enjoys writing and often writes on the topic of staying safe in and around your work environment.